I. Field of the Invention
The present invention relates generally to a construction of a staple for compressive implantation into the mandibular jaw, a drill guide assembly for use during implantation, and a method for insertion of the staple utilizing the drill guide assembly.
II. Description of the Prior Art
Mandibular staples such as disclosed in Applicant's prior patents, U.S. Pat. Nos. 3,414,975, 3,664,022 and 3,895,444, are known for implantation in a mandible or lower jaw. The mandibular staple has been implanted for rehabilitation of various types of mandibular deformities. These deformities, which occur through aging or wasting away of bone tissue, prevent the anchoring of a dental appliance against accidental dislodgement. The mandibular staple is implanted to provide additional support against dislodgement of the dental appliance or prosthesis.
Applicant's prior staple, such as disclosed in U.S. Pat. No. 3,895,444, features a curvilinear support plate, a pair of threaded transosteal pins and a plurality of mushroom shaped fasteners. The shape of the support plate conforms to the curvilinear shape of the front end of the jaw bone. The pair of threaded transosteal pins extend outwardly from the support plate to extend through the jaw bone to receive threaded support nuts. The plurality of mushroom shaped fasteners extend upwardly from the plate for insertion into holes drilled in the jaw bone for securing the staple to the jaw bone. The staple is secured to the jaw bone when the penetrated subcutaneous tissue and bone surrounding the pins and mushroom shaped fasteners grows outwardly. The tissue eventually grows into a porous bioceramic coating on the staple to homogeneously lock the staple to the jaw bone. A dental appliance may be removably affixed to the support nuts.
Applicant's prior U.S. Pat. No. 3,664,022 featured a drill guide having a jig bore adapted for abutment with the jaw bone and a yoke member having a pair of spaced apart guide pins. The jig bore is movable on a post to abut the curved front end of the jaw bone to permit the drilling of a plurality of throughbores and blind bores in the mandibular jaw bone, for accepting the pair of pins and the plurality of mushroom shaped fasteners of the staple. The guide pins of the yoke extend to contact a template extending over the upper surface of the jaw.
Applicant's prior staple provides support for retaining a removable prosthesis or appliance. However, the prior drill guide and method of insertion provide an alignment of the transosteal pins of the staple which is substantially angled with respect to a lateral plane of the dental prosthesis and an axis of compression of the jaws. Thus, the dental prothesis is required to accept the staple at an angle to the lateral plane. Formation of the dental prosthesis in this manner is both time consuming and expensive.
Additionally, the prior staple is secured primarily by bone which grows outwardly from the holes to engage the threaded pins and mushroom shaped fasteners. However, the threads of the pins irritated the gingiva. Because alignment of the staple is angled substantially with respect to the axis of compression, and because of the manner of affixation of the staple, fixed installation of a dental appliance is not possible. The staple is not satisfactorily positioned or fixed to support the compressive loads which are generated on the prosthesis during chewing and the like. The prior staple may be used as a stabilizing device for a removable prosthesis. The prior staple may not be satisfactorily used with a prosthesis until the bone grows back around the plurality of pins and fasteners of the staple.
Thus, it would be advantageous to present a staple and method of insertion which would support the compressive forces for permanent installation of a prosthesis and which could be used soon after surgery. Such a staple would permit simpler formation and installation of the prosthesis and greatly reduce the trauma associated with the implant procedure.